Notchwillow: Scientific Calculator — Privacy Policy

Publisher: Zydeno · Contact: [email protected] · Effective: 19 October 2026

Short version: Notchwillow stores your calculation tape, memory, variables and settings only in your browser (storage.local). Nothing is sent to Zydeno or anyone else. There is no account, no analytics, no advertising and no tracking.

What is stored, and where

• The tape: your last 200 calculations (expression, answer, time, angle or number-base mode).
• The line you are typing in the calculator and in programmer mode, so it is not lost when the toolbar popup closes.
• The memory value (M), the variables you name (for example rate = 7.5%), the last unit conversion and your settings (theme, language, number size, separators, mode).
• Everything stays in your browser profile until you delete it in Notchwillow (Settings → Clear the tape, Clear memory and variables) or remove the extension.

Network

Notchwillow makes no network requests. Fonts, icons and code are inside the extension. Unit conversion uses fixed factors built into the extension; there are no currency rates or online lookups.

Permissions

• storage: keeps the tape, memory, variables and settings in your browser.
• contextMenus: adds "Calculate “…”" to the right-click menu when text is selected. When you choose it, the browser passes only the selected text to Notchwillow, which shows it in a calculator tab. Notchwillow cannot read or change the pages you visit and has no access to websites.

Notchwillow does not read the clipboard. It writes an answer to the clipboard only when you ask for it: the Copy button, Copy in a tape line menu, or Ctrl+C in the calculator with nothing selected.

Backup files

A backup you save is a JSON file that your browser downloads to the place you choose. A backup you restore is read locally and checked completely before anything changes.

Children

Notchwillow does not collect personal data from anyone, including children.

Changes

If this policy changes, the new version is published at https://zydeno.com/calculator/addons/privacy.html with a new effective date.

Contact

Questions and support: [email protected]